1. Field
The subject matter disclosed herein relates to fixed and mobile electronic devices, and more particularly to methods, apparatuses and articles of manufacture for use by one or more fixed electronic devices to generate a reference data report and/or one or more mobile electronic devices to generate an environment report corresponding to a particular environment.
2. Information
Precise and reliable determination by a mobile device of its current altitude above sea level or above or below some other known reference (absolute altitude) may sometimes be useful or even necessary for certain services and applications. For example, the information may be used to determine which floor in a high building a user who has just dialed an emergency call is on when the user either does not know the floor or is unable to convey this to an emergency services responder (e.g. due to language or speech difficulties or a poor call connection). Determination of precise absolute altitude for mobile wireless devices using existing standard positioning methods such as Assisted-Global Satellite Navigation System (A-GNSS), Observed Time Difference of Arrival (OTDOA), Advanced Forward Link Trilateration (AFLT), Enhanced Cell ID (E-CID), etc., to name just a few may not always be possible due to the inherent limitations of these positioning technologies and impediments to receiving and accurately measuring relevant radio signals. For example, depending on the position of the satellites in the sky and the amount of sky cover from nearby buildings, trees and hills etc., altitude resolution for Assisted-GNSS may only be possible within a few hundred feet in an outdoor environment and may not be possible at all inside a building. Other methods such as OTDOA, AFLT or E-CID combined with a terrain or contour map (which may provide a known ground level for any known horizontal location) may be unreliable due to unknown height inside a building.
Barometric pressure sensors in a mobile device can be used to overcome these shortcomings. Barometric pressure sensors in a mobile device measure the atmospheric pressure at the mobile device's location. These pressure measurements can then be used by the mobile device (either in combination with other positioning technologies such as Assisted-GNSS, etc. or on their own) to calculate either (i) the mobile device's absolute altitude given knowledge of the current atmospheric pressure at sea level (or some other well defined reference level) or (ii) the mobile device's relative altitude above (or depth below) local ground level. Other sensors in the mobile device such as a thermometer, light sensor or hygrometer may be used to obtain other data concerning the local environment and determine or help determine whether a mobile device is outside or indoors which may additionally assist computation of the mobile devices absolute or relative altitude.